03 Feb What is an electric fuse?

Physics is one of the broader subjects that fall under the category of Science. The main object of all three divisions, Biology, Physics and Chemistry are to understand the law of the universe and everything in it. Physics can sound very daunting to the students because of the various tough topics and areas of Physics but if guided properly any student can score more in physics with less effort.

Everyone one of you taking physics tuition may have heard about electric fuses. In this physics tuition lesson, we will learn about the use of electric fuses. Your physics tuition helps you to understand things which we come across every day. An electric fuse is a device that breaks an electric circuit when the current becomes excessive because of a ‘short’ or ‘overload’. A ‘short’ occurs when two live wires touch each other. Due to this a large surge of current flowing through the wires. As a result the wires can heat up excessively or start a fire. An ‘overload’ occurs when too many electrical appliances are plugged into a single circuit. In this situation, more current starts flowing through the wires generating the same problem of heat or fire. The fuse helps to prevent such occurrence of ‘short’ or ‘overload’.

Electric fuses are used in almost all the electrically operated instruments. It is to protect them from a possible damage caused by excessive flow of current. Do you know what an electric fuse is and how it works?

A fuse is essentially a small piece of wire which has a low melting point. It is usually made of a tin and lead alloy. The fuse wire is fitted on a carrier called the fuse holder. The fuse holder is made of porcelain, ebonite or some other insulating material.

There are two kinds of fuses: plug fuses and cartridge fuses. Plug fuses screw into sockets and carry light electrical loads. They are mainly used in circuits for domestic light and small appliances. Cartridge fuses are narrow cylinders that slide into spring loaded brackets.

So how does a fuse work? A fuse is connected to the live wire of the connecting cord of an appliance. It allows a current to flow if it is less than its rating (the maximum safe current that can flow through a fuse without exploding). If the current becomes larger, it becomes hot and melts. The circuit is then broken. This prevents the appliance from getting damaged.

One should use a fuse of appropriate rating with a particular appliance. If there is no fuse in place, the appliance may get damaged.

We hope you liked your physics tuition lesson. We will teach you more interesting stuff in the next physics tuition lesson.